Oil spill takes toll on biodiversity

By Jonathan L. Mayuga

Nearly a month after its sinking, the ill-fated vessel which was carrying 800,000 liters of industrial oil continues to cause havoc, taking its toll on the rich biodiversity of coastal and marine ecosystems in the affected towns.

An estimated 20,000 liters of industrial oil from the sunken tanker are seeping out of the vessel.

So far it has already affected nearly a million hectares of coastal areas in 10 towns of the province of Oriental Mindoro, one in the Antique province and two towns in Palawan province.

The affected Oriental Mindoro towns are Naujan, Pola, Pinamalakayan, Gloria, Bansud, Bongabong, Roxas, Mansalay, Bulalacao and Calapan; Agutaya and Taytay in Palawan; and Caluya in Antique.

State of calamity

POLA is one of the severely affected towns, with the health effect of the oil spill taking its toll on the community. Some 120 people have fallen ill and were taken to the hospital after having been exposed to the oil’s toxic smell. They experienced nausea, headache and vomiting.

The whole province of Oriental Mindoro has been placed under a state of calamity; the same with Caluya in Antique

Locally managed marine protected areas—which are set aside for conservation because of their importance as a marine habitat— are at risk of devastation.

Also facing serious threats in the affected areas are the mangrove forests, seagrass beds and corals that are important ecosystem-building species that keep the coastal and marine environment healthy.

Last Tuesday’s news reports said that oil slick has already reached Verde Island, threatening the Verde Island Passage (VIP), a region described by scientists as “the world’s center of marine biodiversity, “one of the most productive ecosystems in the world which supports the livelihood of over 2 million people.

Long-term negative impact

DEPENDING on the severity, the long-term economic and environmental impact of oil spills can never be overemphasized. Most of the time, oil has lethal effects on the environment and it will take years, or even decades, for an affected environment to recover back to health.

But the extent and severity of oil spills can be cushioned or minimized.

Paul Horsman of Greenpeace told the BusinessMirror through e-mail on March 17 that, generally, when oil is spilled into the environment, it has an impact on both the ecosystem and communities that live alongside and within the ecosystem.

“The impact is always negative and, although the ecosystems and communities do survive to a postspill state, the scar remains,” he said.

Greenpeace has been campaigning against fossil fuel and has witnessed its catastrophic impact, including some of the most devastating destructive oil spills in history.

“The extent and severity of an oil spill depend on many things, all of which work in combination to cause the eventual documented impact,” he said.

Horsman, a marine biologist with degrees from Newcastle University and Portsmouth Polytechnic, is an international campaigner at the forefront of advocacy on environmental and peace issues in different countries for over 25 years. He has led Greenpeace teams in response to a number of other oil spills including the 1994/95 spills from pipelines in the Russian Arctic and the BP Deepwater Horizon in 2010.

‘Highly toxic’ ACCORDING to Horsman, the extent of severity of the oil spill also depends on the type of oil spilled into the environment.

“Whether it is light or heavy oil; whether it is a product oil [after refining] and what type of product it is. Generally, product oils are more toxic than crude oils,” he said.

Light oils have more volatile chemicals that evaporate and/or are absorbed into the water, he said.

“These are toxic but generally do not last as long in the environment as the heavier oils,” he added.

On the other hand, heavy oils are some of the most difficult oils to deal with, he said.

“They stay much longer in the environment and are not easily broken down. The bunker [oil] is often an issue with shipping accidents as it is the fuel of the ship and it’s a heavy oil,” Horsman explained.

Effects on coastal environments ACCORDING to Horsman, oil spills have an adverse impact on both plants and animals, including those that occur in rocky shores.

“Rocky shores are generally more exposed to waves that can both spread and break up oil. The oil coats and suffocates the animals and plants that are attached to or grow on the rocks. Oil can remain for years in cracks and crevices as a tarry residue. Rock pools often accumulate oil,” he explained.

Like pebble beaches, sandy beaches, which is known in many coastal areas affected by the oil spill in Mindoro are expected to take its toll for the long haul, he said, as the oil coats the beach.

The oil, he said, can cause suffocation as there are many different animals that live in burrows in the sand, again, depending on the type of sand.

“Oil can penetrate such burrows,” he said.

Mudflats and salt marshes, he said, are also not spared by oil spills, including the species that feed on these important ecosystems, like migratory birds.

Mudflats and salt marshes are much smaller and the movement of the water much slower.

“The oil spreads further and can stay in such areas for long periods,” he noted.

Horsman added that mangroves and coral reefs can suffer extensive damage from oil spills. He explained that mangroves are ecosystems where the wave action is small and the oil can spread much further. This wave movement will result in suffocating young mangrove shoots and burrowed animals, he said.

Lethal effects

DR . Resurreccion Sadaba, chairman of the newly created special task force of the University of the Philippines Visayas (UPV), said oil has a lethal effect to marine life and the environment.

“Physical smothering or covering of mangroves, corals and seagrass can impair their physiological functions,” Sadaba told the BusinessMirror in a telephone interview on March 17,

Another mechanism, he said, is the chemical toxicity of oil that can give rise to the lethal and sublethal effects of the oil that can cause impairment of species, including the ability to breathe naturally.

The changes in the ecology primarily because of the loss of key organisms in that community and the possibility of a takeover of opportunistic species on the habitat can also cause biodiversity loss.

As one or two organisms are lost, the food chain is disrupted, which can also lead to the mass extinction of species in the affected ecosystem.

“There are other indirect effects like the loss of the habitat, or the shelter, and consequent elimination of ecologically-important species,” Sadaba said.

Oil spill response

ACCORDING to Sadaba, responders to the oil spill should be very careful in removing oil.

He said that once oil has started to coat mangroves, corals and seagrass, their death becomes inevitable, but this can be minimized by properly removing the oil.

In mangrove areas, saplings and seedlings are likely to perish if they are heavily coated. He noted that bigger mangroves could also die depending on the severity of the oil cover.

“Once smaller trees are covered, the leaves will slowly turn yellow after a week. Eventually, if its ability to release the salt is impaired because of the oil covering, then it will eventually die,” he explained.

Sadaba explained that removing the oil gently from the affected mangroves, corals and seagrass will help them survive.

However, in most cases, he said natural attenuation or weakening of its impact is the best cure for oil spills.

“Once the oil is already there, one option is natural attenuation. Allow the ecosystem’s natural recovery,” he said.

“There’s a saying that once the oil is there, the best action is ‘no action.’” he said.

The daily tidal flushing, he said, is powerful and can clean the oil.

“All you have to do is to collect the oil being removed by the tidal flushing,” Sadaba said.

This can be done by making booms to collect the oil going in and out of mangrove forests, seagrass beds and even coral reefs.

Do’s and don’ts

THE UPV has come up with a series of public advisories on how to best remove oil in coastal areas.

Some of the “guidelines” aim to reduce the risk of disaster—essentially oil’s lethal effect on health and the environment—while ensuring that the process will not do more harm.

In removing oil, the UPV Task Force highlighted the need to identify duly accredited waste collectors, and of a dump site for collected oil and oil-soaked debris. For health and safety reasons, the collected oil and oil-soaked debris should be sealed and properly disposed of.

For cleanup workers, the UPV said the local government unit should provide supply to the workforce, and coordinate with the Department of Social Welfare and Development for cash for work program.

Cleanup workers should be physically fit, not suffering from respiratory problems, and should be provided with personal protective equipment.

The UPV Task Force recommends manual removal of oil, and use of commercially available or organic sorbents.

Vacuum cleaning, sediment reworking, vegetation cutting, removal, and application of solidifiers should be strictly prohibited.